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- Educational data mining for tutoring support in Higher Education: a web-based tool case study in engineering degreesPublication . Prada, Miguel Angel; Dominguez, Manuel; Vicario, Jose Lopez; Alves, Paulo; Barbu, Marian; Podpora, Michal; Spagnolini, Umberto; Pereira, Maria João; Vilanova, RamonThis paper presents a web-based software tool for tutoring support of engineering students without any need of data scientist background for usage. This tool is focused on the analysis of students' performance, in terms of the observable scores and of the completion of their studies. For that purpose, it uses a data set that only contains features typically gathered by university administrations about the students, degrees and subjects. The web-based tool provides access to results from different analyses. Clustering and visualization in a low-dimensional representation of students' data help an analyst to discover patterns. The coordinated visualization of aggregated students' performance into histograms, which are automatically updated subject to custom filters set interactively by an analyst, can be used to facilitate the validation of hypotheses about a set of students. Classification of students already graduated over three performance levels using exploratory variables and early performance information is used to understand the degree of course-dependency of students' behavior at different degrees. The analysis of the impact of the student's explanatory variables and early performance in the graduation probability can lead to a better understanding of the causes of dropout. Preliminary experiments on data of the engineering students from the 6 institutions associated to this project were used to define the final implementation of the web-based tool. Preliminary results for classification and drop-out were acceptable since accuracies were higher than 90% in some cases. The usefulness of the tool is discussed with respect to the stated goals, showing its potential for the support of early profiling of students. Real data from engineering degrees of EU Higher Education institutions show the potential of the tool for managing high education and validate its applicability on real scenarios.
- Graphical simulator of mathematical algorithms (GraSMA)Publication . Balsa, Carlos; Alves, Luís M.; Pereira, Maria João; Rodrigues, Pedro JoãoOur goal is to develop an interactive software GraSMA that illustrates the execution of mathematical algorithms in the context of numerical methods. We want to create a working tool for teachers and learning tool for students. To achieve it we only use free software (as it is the Open Source software). The strategy followed was to extend the original algorithm code, implemented in Octave, with inspector instructions, recording in a XML (eXtensible Markup Language) file everything that happened during the execution. Subsequently, the XML file is parsed by a Java application that graphically represents the mathematic objects and their behaviour during execution. In this paper, we report the procedures followed, the difficulties encountered and the first results we achieved.
- CaVa: An example of the automatic generation of virtual learning spacesPublication . Martini, Ricardo; Araújo, Cristiana; Henriques, Pedro Rangel; Pereira, Maria JoãoIn order to construct web Learning Spaces (LS), more than collect and digitalize information, a powerful data extraction and querying engine and a sophisticated web publishing mechanism are needed. In this paper, a system to automatically construct those learning spaces based on a digital repository is presented. The system takes XML files from repositories and populates an ontology (representing the knowledge base, the core of our system) to create the triples internal representation. A Domain Specific Language (CaVaDSL) will be used to specify the learning spaces based on that ontology. The formal description, written in that DSL, will be processed by Cavagen engine to generate the final LS.
- Técnicas y herramientas para regular la seguridad en web services basados en WSDLPublication . Bernardis, Hernán; Bernardis, Edgardo; Berón, Mario; Riesco, Daniel; Pereira, Maria JoãoEl desarrollo de sistemas en la actualidad ha mutado, siguiendo la tendencia mundial de migración hacia la nube. Se logra mayor escalabilidad al construir sistemas con módulos distribuidos en la red, en donde el sistema final es la combinación de un conjunto de módulos distribuidos en la nube. Este concepto ha funcionado a lo largo de la historia por medio de diferentes arquitecturas tecnológicas - RPC, RMI, etc. - pero, desde hace algunos años, los servicios web han sido la arquitectura de mayor popularidad. Su independencia de la arquitectura tecnológica subyacente junto con su aprovechamiento de los protocolos ya definidos de internet son algunos de los motivos impulsores de su popularidad. En el caso particular de esta investigación, el objeto de estudio son los servicios web con descripciones en WSDL. La idea de este trabajo consiste en detectar y - de ser necesario - modificar el nivel de entendimiento que posee la descripción de un servicio web para minimizar las vulnerabilidades que este pueda tener al estar publicado en la nube. Para detectar estas vulnerabilidades, es primordial primero comprender el servicio web y, por ende, su descripción. En este artículo se describe una línea de investigación centrada en facilitar la comprensión de Servicios Web mediante el análisis de sus especificaciones WSDL. Este análisis sirve como base para el cálculo del grado de entendimiento del mismo y, en base a esta medida, determinar qué acciones se deben tomar, en caso de que corresponda, para cambiar su grado de entendimiento ocultando vulnerabilidades.
- Problem domain oriented approach for program comprehensionPublication . Pereira, Maria João; Berón, Mario; Cruz, Daniela; Oliveira, Nuno; Henriques, Pedro RangelThis paper is concerned with an ontology driven approach for Program Comprehension that starts picking up concepts from the problem domain ontology, analyzing source code and, after locating problem concepts in the code, goes up and links them to the programming language ontology. Different location techniques are used to search for concepts embedded in comments, in the code (identifier names and execution traces), and in string-literals associated with I/O statements. The expected result is a mapping between problem domain concepts and code slices. This mapping can be visualized using graph-based approaches like, for instance, navigation facilities through a System Dependency Graph. The paper also describes a PCTool suite, Quixote, that implements the approach proposed.
- Estrategias para facilitar la comprensión de programasPublication . Berón, Mario; Uzal, Roberto; Henriques, Pedro Rangel; Pereira, Maria JoãoLa Comprensión de Programas es una disciplina de la Ingeniería de Software cuyo objetivo es proveer Modelos, Métodos, Técnicas y Herramientas para facilitar el estudio y entendimiento de los sistemas de software. A través de un extenso estudio y experiencia en el desarrollo de productos de comprensión se pudo comprobar que el principal desafío en esta área consiste en: Relacionar el Dominio del Problema con el Dominio del programa. El primero hace referencia a la salida del sistema. El segundo a las componentes de software usadas para producir dicha salida. La construcción de este tipo de relación es muy compleja e implica el estudio de disciplinas tales como: Modelos Cognitivos, Visualización de Software, Estrategias de Interrelación de Dominios y Métodos de Extracción de la Información. En este artículo se presentan líneas de investigación cuyos objetivos son: • Analizar los productos de comprensión existentes. • Construir productos innovadores basados en los conceptos comunes a las grandes áreas mencionadas en el paragrafo anterior.
- Software development with grammatical approachPublication . Kosar, Tomaz; Mernik, Marjan; Zumer, Viljem; Henriques, Pedro Rangel; Pereira, Maria JoãoThe paper presents a grammatical approach to problem solving. It supports formal software specification using attribute grammars, from which a rapid prototype can be generated, as well as the incremental software development. Domain concepts and relationships among them have to be identified from a problem statement and represented as a context-free grammar. The obtained context-free grammar describes the syntax of a domain-specific language whose semantics is the same as the functionality of the system under implementation. The semantics of this language is then described using attribute grammars from which a compiler is automatically generated. The execution of a particular program written in that domain-specific language corresponds to the execution of a prototype of the system on a particular use-case.
- Clasificaciones: un mecanismo de herencia múltiple para la construcción de modelos fáciles de comprender y mantenerPublication . Aristiaran, Martín; Berón, Mario; Henriques, Pedro Rangel; Pereira, Maria JoãoLos actuales mecanismos de Múltiple Herencia(MH) han resuelto gran parte de sus problemas históricos como el problema del diamante y la herencia de distintas implementaciones de métodos y atributos con el mismo nombre. Sin embargo, los modelos producidos por estos mecanimos presentan al menos uno de los siguientes problemas: i) No contienen información acerca de como es posible extenderlos asegurando la inexistencia de con ictos, o ii) El modelo creado no puede inferirse a partir de características de los elementos del dominio. La existencia de esos problemas agrega gran complejidad al mantenimiento de esos modelos, lo cual desanima el uso de la MH. En este contexto, este artículo describe una línea de investigación cuyos principales objetivos son crear mecanismos de MH que: i) Brinden una solución a los dos problemas mencionados anteriormente, lo cual facilita el mantenimiento de los modelos, y ii) Produzcan modelos inteligibles y expresivos.
- Program comprehension for domain-specific languagesPublication . Pereira, Maria João; Mernik, Marjan; Cruz, Daniela; Henriques, Pedro RangelIn the past, we have been looking for program comprehension tools that are able to interconnect operational and behavioral views, aiming at aiding the software analyst to relate problem and program domains in order to reach a full understanding of software systems. In this paper we are concerned with Program Comprehension issues applied to Domain Specific Languages (DSLs). We are now willing to understand how techniques and tools for the comprehension of traditional programming languages fit in the understanding of DSLs. Being the language tailored for the description of problems in a specific domain, we believe that specific visualizations (at a higher abstraction level, closer to the problem level) could and should be defined to enhance the comprehension of the descriptions in that particular domain.
- VisualLISA: visual programming environment for attribute grammars specificationPublication . Oliveira, Nuno; Henriques, Pedro Rangel; Cruz, Daniela; Pereira, Maria JoãoThe benefits of using visual languages and graphical editors are well known. In some specific domain it is really crucial to program with graphical representations, icons, geometric objects, colors and so on. Nowadays it is possible to easily implement a visual language, constructing, automatically, visual editors for it. In this paper we want to emphasize how it is possible to easily specify a huge amount of complex information, associated with an attribute grammar, using graphical objects and a very intuitive modular approach. For that purpose we present a new visual language to specify attribute grammars (called VisualLISA) and we present also a modular approach that uses VisualLISA in an integrated editor to draw attribute grammars.